1. Field of the Invention
The present invention relates to a surgical instrument for holding a needle and suturing the tissues, for example, during the coronary artery bypass grafting of heart under the observation by an endoscope.
2. Description of the Related Art
The following procedure is known for conducting, for example, the coronary artery bypass grafting of heart under the observation by an endoscope. That is, a bypass procedure is known in which an endoscope, a surgical instrument as a needle-holder, and a forceps are inserted into a chest cavity via a trocar piercing a thoracic wall, part of the coronary artery is cut with the scissors-like forceps to provide an anastomotic opening, an internal thoracic artery is guided to the anastomotic opening with a grasping forceps, and the internal thoracic artery is connected by anastomosing to the anastomotic opening with the surgical instrument.
Furthermore, a surgical instrument having a structure comprising an insertion unit having a curved section at the distal end and also comprising jaws serving as a pair of treatment units at the distal end section of the insertion unit, those jaws being capable of opening and closing and turning about the axis of the insertion unit is known from U.S. Pat. No. 5,951,575 as a surgical instrument suitable for such a procedure, that is, as a needle-holder for holding a needle and anastomosing the tissue.
As described above, this surgical instrument has jaws serving as a treatment unit that can be opened, closed, and turned in the distal end section of the insertion unit. However, the turn of the jaws is carried out by turning a dial for turn operation that is provided in an operation unit, whereas the operation of opening and closing the jaws is carried out by operating an opening and closing lever that is provided in the operation unit.